Checking device



March 22, 1960 R. T. HALL 2,929,147

CHECKING DEVICE Filed oct. zo, 195s 2 sheets-sheet 1 l INVENTUR.

ROBERT THALL,

BY r

/ m f "l 114.

March 22, 1960 R. T. HALL 2,929,147

CHECKING DEVICE Filed Oct. 20, 1955 2 Sheets-Sheet 2 INVENTOR. ROBERT 7. HALL United States Patent CHECKING DEVICE Robert T. Hall, Birmingham, Mich., assgnor to Kelsey- Hayes Company, a corporation of Delaware Application October 20, 1955, Serial No. 541,625

3 Claims. (Cl. 33-174) The invention relates to checking devices and refers more particularly to checking devices for indicating variations in dimensions of spaced portions of a surface of an article. More specifically, the invention has reference to checking devices for indicating unevenness or wave of circumferentially spaced portions of an annular surface of an article.

The invention has for one of its objects to provide a checking device having relatively movable contact members which are simultaneously engageable with spaced portions of an article and are operable to control the operation of the checking device to indicate the relative positions of the contact members and thereby indicate variations in the surface being checked of the article.-

The invention has for other objects to provide a checking device having means for moving the contact members out of engagement with the article to permitvits removal and the insertion of another article and to provide a checking device having means for yieldably moving and holding the contact members against the article.

These and other objects of the invention will become apparent from the following description taken in connection with. the accompanying drawings in which- Figure 1 is a side elevation of a checking device embodying the invention;

Figure 2 is a plan view of the checking device with the article broken away and in section and with diagrammatic illustration of various elements used in connection with the checking device;

Figure 3 is a view similar to Figure 1 showing a modification;

Figure 4 is a plan view of Figure 3.

The checking device has the base 1, the support 2 and the carrier 3, The base 1 has mounted thereon the upright pilot 4. The support 2 has the body 5 and the end furcations 6 and 7 and the support is xedly secured to the upper surfaceof the base l by the screws 8 extending through the body into the base 1. The carrier 3 has the body 9 and the lower and upper end arms 10 andll, respectively, the body 9 extending between the end furcations 6 and being journalled on the pivot pin 12 which extends through the body 9 and the turcations 6. The body is formed with the upwardly extending flange 13 in which is xedly mounted the contact member 14 having a convex partly spherical end engageable with the surface being checked of the article. The lower end arm 10 extends beyond the end furcations 6 and the upper end arm 11 extends above the end furcations 7. The lower end arm has movably mounted thereon the contact member 15 extending adjacent the contact member 14 and also having a convex partly spherical end engageable with the article surface being checked. In the present instance, the article is a brake drum having the annular centrifugally cast liner 16 inside and fused to the annular ange 17 of the shell 18. The contact members 14 and 15 are located to engage circumferentially spaced portions of the radially inner braking surface of the liner at a predetermined distance from each other. The predetermined distance is a minor portion of the circumference of the braking surface, so that the device does not check or indicate the run-out or eccentricity of the braking surface as a whole. The contact member 15 is mounted on the reciprocable gaging spindle 19 of the gage head 20 which is iixedly secured to the upper surface of the lower end arm 10 of the carrier 3. y

The upright pilot 4 has the reduced upper end portion 21 of a size to extend through and lit the central hole in the web 22 of the brake drum shell. This pilot also has the annular shoulder 23 for engaging the portion o f the web immediately surrounding the central hole so that the brake drum is rotatably supported. The pilot is also positioned such that the liner 16 of the brake drum is in position to be engaged by the contact members 14 and 15.

For the purpose of moving the contact members 14 and 15 out of engagement with the liner 16 of the brake drum to permit the removal of the brake drum and the insertion of another brake drum, I have providedth'e cam 24 extending between the end furcations 7 and lixedly secured to the shaft 25 by the pin 26. The shaft extends between the end furcations 7 and is journalled therein and preferably has integral with one end thereof the transversely extending handle portion 27 by means of which the cam can be rotated in a counterclockwise direction to lift the upper end arm 11 and thereby swing the carrier 3 in a counterclockwise direction to move the contact members 14 and 15 inwardly and downwardly away from the liner 16. The cam preferably has the ilat surface 28 which, when in engagement with the upper end arm, will hold the cam in adjusted position.

In order to yieldably move the contact members 14 and 15 into engagement with the liner 16,.there is the weight 29 adjustably secured on the rod 30 which in turn is threadedly secured in thel end of the upper arm 11 beyond the cam 24. The cam is so shaped that when the cam is being rotated in a clockwise direction to the position shown in Figure 1, it allows the weight to swing the carrier in a clockwise direction and move the contact members 14 and 15 into engagement with the liner 16.

The gage head 20 is electrically connected to the power unit 31 which in turn is electrically connected t6 the meter 32. The power unit and meter may be mounted in any desired position and, as shown, they are mounted onA the base 1. The gage head, power unit and meter are standard or conventional elements of a comparator engineered and produced by a well-known manufacturing concern in the United States.

As shown in Figures 3 and 4, the checking deviceis for use in indicating dimensional variation or run-out of spaced circumferential portions of an annular surface, such as a tire bead seat of a tire rim 33. The rim is rfxedly secured to the Wheel body 34 of a motor vehicle wheel which is mounted on the pilot 35 rotatably mounted on the base or table 36.` As shown, the bolt holes in' the mounting flange 37 of Jthe wheel body or at least certain of these bolt holes are engageable withv the upright dowel pins 3S carried by the pilot.

The checking device has the same elements as illustrated in Figures 1 and 2 with the gage head 39 mounted on the carrier 4) which is a slide movable radially with respect to the wheel and directly carrying the fixed contact member 41 corresponding to the contact member 14. The movable contact member 42 is directly mounted on the gage head 39 in` the same manner as the contact member 15 is mounted on its gage head. The slide in the present instance is mounted on a portion of the base which forms the support for the slide and is adapted to be moved radially by means of the air cylinder 43 having ports at its opposite ends connected by the tubes 44 r"an'd-Sf-toa soienoid'foperated valve 46, the solenoid of whiclriselectrically connected to the limit switch-'47. The solenoid operated valve and the limit switch are mounted on the base or table 36 withrthe limit switch '-iocated sothat'its 4'contact arm-48 is engageable by the lower tire retaining flange ofthe rimduring'the nal @downward movement `of `the'wheel body when kbeing mounted on the pilot.

The invention atfordsa device for checking-dimensional Y'variation or-unevenness, in the radial sense, of surface `portions of anannular object which are very closely spaced circumferentially thereof, in relation to or by comparison `Vwith the total circumference or circumferential extent 4foffthe checked surface. Rather than `a check lof overall -run-out or eccentricity of the checked surface as a whole, aapplicantsrdevce makes possible the taking of an infinite `number'of readings, veach onthe basis of aspacing of feeler @elements lof, sayyone inem-about the periphery of an objectsuch'asan automotive brake drum or Wheel rim of vastlygreaterperipheral extent. Overall unevennesls,ec

centricity or run-out is ignored.

What I'claim as'my invention is: `-"1."In"a 4checking `device yfor indicating variation-'in aradial 'dimensionsvof circumferentiallyspace'd portions of :an annularsurface `of an'annular articlefasupport for jsupportingthe article forrotationabout a fixed axis, a rcarrier, means guiding said carrier for movement toward fand 'away from said lfixed axis, 'said carrier having a A'siri'gleftixed portion in position to engagesaid surface of 'tl'iearticle on said support, said single xed portion being the onlytixed portion of said carrier engageable with said surface 'ofthe article on said support and being in the `-form of a contact member shaped to have point contact with said surface of the article, a second contact member mounted on `said carrier for movement in .the direc- `rtion of carrier movement, said second contact member being positioned to engage said surface of the article on said'support and being shaped to have point contact therewith, said contact members being closely spaced apart circumferentially with respect to said fixed axis for simul- `taneous engagement with closely circumferentially spaced portions of 'said surface of the article on' said support, means'for urging said carrier in one direction relative to said vfixed axis to maintain said contact members in continuous engagement with the said surface during rotation of the article, and gage means operated by movement of said second contact member relative to said carrier.

2`.'In a checking device for indicating variation in radial dimensions of circumferentially spaced portions of an annular surface of an annular article, a base having means `for supporting the article for rotation about a ixed axis, a carrier, means mounting said carrier on said base'for guided movement toward and away `from said fixed axis, said carrier having a single xed portion in ,pmtition to engage said surface of the'artcle on said support, said single fixed portion. being the only Ytix'e'd portion of said carrier engageable with said surface of the article on :said support and being inthe form of a contact memher shaped to have point contact with said surface of the article, a second contact member mounted on said carrier for movement in the direction of carriermovement, said second contact member being positioned to engage said surface of the article on said support and being shaped to havepoint-contact" therewith, 'said' contact members being closely spaced apart circumferentially with respect to said fixed axis for simultaneous engagement with closely circumferentially spaced portions of said surface of the article on said base, tiuid pressure means for yieldably urging said carrier in one direction relative to said fixed axis to maintain said contact'members in continuousengagement with said surface during rotation of the article, and gage means operated by movement of said second contact member relative'to said carrier.

3. In a checking device :for indicating variation in radial dimensions of circumferentially spaced portions of an annular surface of an annular article, a base having means for supporting the article' for rotation about a fixed axis, a carrier, means pivotally mounting said carrier on said base for movement toward and away from said lixed axis, said carrier having a single fixed portion in position toengage said# surface ofthe article on said support, said single fixed-portion being-'the 'onlyiixed portionrof said carrier engageable'=withsa-dsurface of the artcle'on said support and being l-n --the ffo'rm of a v-contact member shaped ito lhaverf-pontcontactwith y*said "surface "ofI the artic1e,-a=`secorid1 contact memberrnounted on said carrier for movement in the direction of carrier'movement, said v second f'con'tact member 'being positioned vto engage vsaid 'surface Yof the I"article Yon said "support and 'being shaped ttrhave point vcontact therewith, said contact members being'c1osely-spaced-apart circumferentially with respect 'to'saidtixedaxisfor simultaneous engagement withclosely circumferentiallyspaced portions 4of said .surface of the artielefon-'said base, a'weight "for normally swinging said "carrier'relativefto its pivotal mounting in one direction relative to saidltixedaxis'to engagersaid contact members withsaid surface and'to yieldably maintain said contact `members in continuous engagement with said Vsurface dur- `ingrotation of the article, a cam forswinging said carrier in the opposite-,direction relative to its pivotal mounting to-move*saidrcontact'members away-from thearticle and out of engagement with thev surface thereof, and gage means operated 1by movement of said second contact member relative tosaidcarrien References" Cited' in 'the file vof this r.patent UNITED STATES PATENTS -703,725 vvHardinge July' 1, 1902 802,470 Picard Oct. 24, 1905 812,042 Hudson Feb. 6, 1906 1,317,459 Rouanet Sept. 30,1919 1,539,896 Claybournl June 2, 1925 r1,997,639 '-'Hetherington Apr. 16, 193s "2,016,420 Y ',ngst.- A Oct. 8, 193'5 V'2,420,111 -Lear. May 2o, 1947 12,427,152 'Moore Sept. 9, 1947 2,487,628 Aller NOV. 8, 1949 2,613,447 'Brouwer Oct. 14, 1952 2,624,949" 'Schie'r'na'n Jan. 13, 1953 ,2,648,135 Gates Aug. 11, 1953 2,657,468 Lyons Nov. 3, 1953 2,662,297 Reicheter Dec. 15, 1953 

